AbstractThis paper explores the potential of using a historical sociolinguistic approach to interrogate the extensive lists of personal names found in medievallibri vitæ. So far, these lists have mainly been exploited in historical and a few onomastic studies, with a focus on name etymology and personal naming practices. Both the linguistics of the names and sociolinguistic perspectives remain to date underexamined. In this contribution, we explore possible sociolinguistic research questions, and present methodological challenges and preliminary results on the basis of four case studies from two examples, thelibri vitæof Thorney Abbey and Reichenau. The case studies examine autographs, choice of script and language, and dialect adaptation. Our main interest lies in the modelling and explanation of graphic and linguistic variation in the names. Our particular focus is on the status of the respective vernacular languages involved (Old English and Old High German) and in the conclusions we can draw from these documents about their underlying writing traditions in general, and scribal training and practices in particular.